FastAPI with Kubernetes, Prometheus, and Grafana Monitoring Tutorial

A comprehensive 6-step guide to deploying FastAPI applications on Kubernetes with robust monitoring using Prometheus and Grafana.

Overview

This tutorial covers deploying a FastAPI application to Kubernetes with complete monitoring setup. You'll learn:

• Setting up Kubernetes deployments for FastAPI applications
• Configuring service discovery and monitoring with Prometheus
• Creating Grafana dashboards for metric visualization
• Troubleshooting common deployment issues

Step 1: Deploy FastAPI on Kubernetes

Implementation Steps

• Containerize FastAPI using uv package manager
• Create and apply Kubernetes Deployment and Service
• Configure proper labels and selectors

FastAPI Deployment Configuration

apiVersion: apps/v1
kind: Deployment
metadata:
  name: fastapi-app
spec:
  replicas: 2
  selector:
    matchLabels:
      app: fastapi
  template:
    metadata:
      labels:
        app: fastapi
    spec:
      containers:
        - name: fastapi
          image: cshorten/fastapi-app:latest
          ports:
            - containerPort: 8000
---
apiVersion: v1
kind: Service
metadata:
  name: fastapi-service
  labels:
    app: fastapi
spec:
  selector:
    app: fastapi
  ports:
    - name: http
      protocol: TCP
      port: 80
      targetPort: 8000

Step 2: Install Prometheus for Monitoring

Implementation Steps

• Install Prometheus Operator using Helm
• Verify StatefulSet deployment
• Check service discovery in Prometheus UI

Installation Commands

helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update
helm install prometheus-stack prometheus-community/kube-prometheus-stack -n monitoring --create-namespace

Step 3: Configure Prometheus Service Discovery

ServiceMonitor Configuration

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: fastapi-servicemonitor
  namespace: monitoring
  labels:
    release: prometheus-stack
spec:
  selector:
    matchLabels:
      app: fastapi
  endpoints:
    - port: http
      path: /metrics
  namespaceSelector:
    matchNames:
      - default

Common Issues and Solutions

Step 4: Verify Prometheus Configuration

Debugging Commands

# Port forward Prometheus service
kubectl port-forward -n monitoring svc/prometheus-stack-kube-prom-prometheus 9090

# Check Prometheus logs
kubectl logs -l app.kubernetes.io/name=prometheus -n monitoring --tail=50

# List ServiceMonitors
kubectl get servicemonitor -n monitoring

# Show pod labels
kubectl get pods -n monitoring --show-labels

# Restart Prometheus
kubectl rollout restart statefulset prometheus-prometheus-stack-kube-prom-prometheus -n monitoring

Step 5: Grafana Dashboard Setup

Access Configuration

# Port forward Grafana service
kubectl port-forward -n monitoring svc/prometheus-stack-grafana 3000

# Get admin password
kubectl get secret -n monitoring prometheus-stack-grafana -o jsonpath="{.data.admin-password}" | base64 --decode ; echo

Prometheus Data Source Configuration

1. Navigate to Configuration → Data Sources
2. Select Prometheus
3. Set URL to: http://prometheus-stack-kube-prom-prometheus.monitoring.svc:9090
4. Save and test connection

Step 6: Metric Visualization

Essential PromQL Queries

Next Steps

Enhancement Opportunities

1. Metric Expansion

   • Implement Histogram and Summary metrics
   • Add custom business metrics

2. Alert Configuration

   • Set up Prometheus AlertManager
   • Configure alert rules and notifications

3. Scaling Implementation

   • Configure HorizontalPodAutoscaler
   • Define scaling metrics and thresholds

Achievement Checklist

• FastAPI deployment on Kubernetes
• Prometheus metric collection
• Grafana dashboard visualization
• Service discovery configuration
• Basic monitoring setup